The present invention relates generally to powertrains and methods for use with additized dimethyl ether (DME) fuel and, more particularly, to ensuring quality of DME fuel.
There has been substantial interest in recent years in vehicles, particularly trucks that run on dimethyl ether. This is a fuel with very different characteristics from diesel fuel and other hydrocarbon based fuels.
Due to, among other things, the lack of infrastructure for DME fuel, there are concerns with ensuring the fuel does not get contaminated with propane or other hydrocarbons along the supply chain. Propane and DME have similar physical characteristics. It is possible, for example, that consumers will try to put propane in their vehicles designed for use with DME if the price of propane is cheaper, or that a supplier would try to mix propane and DME for cost savings. It is also possible that a consumer who is not able to obtain DME conveniently might choose to use propane if it is more readily available.
There is also a concern that DME will lack the lubricity additive to permit an engine to properly function. DME lacks the natural lubricity needed to lubricate the fuel system components, so lubricity agents are added to the DME. As DM E is a new fuel lacking strong infrastructure, there is not presently a good way to insure the fuel will be properly additized.
It is desirable to provide a method to detect both DME contamination with, among other things, hydrocarbon fuel, and to detect the proper additization of DME with a lubricity agent.
In accordance with an aspect of the present invention, a powertrain arrangement for use with additized Dimethyl Ether (DME) fuel, the additized DME comprising DME and a lubricity additive, is provided. The powertrain arrangement comprises a powertrain comprising an engine adapted for use with the additized DME fuel, a fuel tank, a conductivity sensor in the fuel tank, the conductivity sensor being arranged to transmit a signal corresponding to a conductivity of fuel in the fuel tank, a temperature sensor in the fuel tank, the temperature sensor being arranged to transmit a signal corresponding to a temperature of the fuel in the fuel tank, and a controller configured to receive and process the conductivity signal and the temperature signal and to send a control signal to control functioning of the powertrain in response to the conductivity signal and the temperature signal.
In accordance with another aspect of the present invention, an apparatus for measuring conductivity of additized Dimethyl Ether (DME) fuel, the additized DME comprising DME and a lubricity additive, is provided. The additized DME may include other additives, as well, such as an odorant and whatever else is deemed necessary. The apparatus comprises a conductivity sensor, the conductivity sensor being arranged to transmit a signal corresponding to a conductivity of fuel being measured, a temperature sensor, the temperature sensor being arranged to transmit a signal corresponding to a temperature of the fuel being measured, and a controller configured to receive and process the conductivity signal and the temperature signal and to send a signal in response to a determination that conductivity of the fuel being measured is outside of a predetermined range of conductivity for additized DME at the temperature of the fuel being measured.
In accordance with another aspect of the invention, a method of operating a powertrain arrangement for use with additized Dimethyl Ether (DME) fuel, the additized DME comprising DME and a lubricity additive, is provided. The method comprises sensing conductivity of fuel with a conductivity sensor, transmitting a signal corresponding to the conductivity of the fuel sensed by the conductivity sensor, sensing a temperature of the fuel with a temperature sensor, transmitting a signal corresponding to the temperature of the fuel sensed by the temperature sensor, and processing the conductivity signal and the temperature signal in a controller and sending via the controller a control signal to control functioning of a powertrain of the powertrain arrangement in response to the conductivity signal and the temperature signal.